Moderna, Pfizer-BioNTech vaccines show 90% effectiveness in real-world conditions

 After completing 13-week SARS-CoV-2 testing on 3,950 health care personnel, first responders, and other essential and frontline workers under real-world conditions, US Centers for Disease Control and Prevention (CDC) found that Moderna and Pfizer-BioNTech vaccines’ effectiveness of full immunization (≥14 days after the second dose) was 90% against SARS-CoV-2 infections regardless of symptom status; vaccine effectiveness of partial immunization (≥14 days after the first dose but before the second dose) was 80%. 

62.8% of participants received both recommended mRNA doses and 12.1% received only one dose of mRNA vaccine. Among unvaccinated participants, 1.38 SARS-CoV-2 infections were confirmed by reverse transcription-polymerase chain reaction (RT-PCR) per 1,000 person-days. In contrast, among fully immunized (≥14 days after the second dose) persons, 0.04 infections per 1,000 person-days were reported, and among partially immunized (≥14 days after the first dose and before the second dose) persons, 0.19 infections per 1,000 person-days were reported. These findings indicate that authorized mRNA COVID-19 vaccines are effective for preventing SARS-CoV-2 infection, regardless of symptom status, among working-age adults in real-world conditions.

Participants included physicians and other clinical leads (primary health care personnel) (21.1%), nurses and other allied health care personnel (33.8%), first responders (21.6%), and other essential and frontline workers (23.5%). The majority of participants were female (62.1%), aged 18–49 years (71.9%), White (86.3%), and non-Hispanic (82.9%) and had no chronic medical conditions (68.9%).

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“This study shows that our national vaccination efforts are working. The authorized mRNA COVID-19 vaccines provided early, substantial real-world protection against infection for our nation’s healthcare personnel, first responders, and other frontline essential workers,” CDC Director Rochelle Walensky said.

Earlier, CSIR director-general Shekhar C Mande had talked about bringing the mRNA-based vaccine platform to India which has approved Covaxin (the homegrown government-backed vaccine) and Covishield ( Oxford-AstraZeneca vaccine) to be used for vaccination.

“Today, we don’t have any mRNA-based vaccine platform in the country and Dr (Krishna) Ella and us are already talking about how we actually bring it, and Dr Ella is very confident that we can bring this particular platform in the coming few months,” CSIR director said.

How do COVID-19 mRNA vaccines work?

COVID-19 mRNA vaccines give instructions for our cells to make a harmless piece of what is called the “spike protein.” The spike protein is found on the surface of the virus that causes COVID-19.

COVID-19 mRNA vaccines are given in the upper arm muscle. Once the instructions (mRNA) are inside the immune cells, the cells use them to make the protein piece. After the protein piece is made, the cell breaks down the instructions and gets rid of them.

Next, the cell displays the protein piece on its surface. Our immune systems recognize that the protein doesn’t belong there and begin building an immune response and making antibodies, like what happens in natural infection against COVID-19.

At the end of the process, our bodies have learned how to protect against future infection. The benefit of mRNA vaccines, like all vaccines, is those vaccinated gain this protection without ever having to risk the serious consequences of getting sick with COVID-19.

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